Imaging of biological tissue can aid in the diagnosis of skin cancers, oral cancers, and skin and/or oral burns. Reflectance Confocal Microscopy (RCM) is an imaging method that can show nuclear and cellular details of the biological tissue. For example, RCM can show details of the superficial epidermis of the biological tissue, the underlying papillae of the biological tissue, and the superficial reticular dermis of the biological tissue (e.g., to a depth of 250 μm). RCM can also show details of microcapillary blood flow in the upper dermis of the biological tissue. RCM imaging capabilities can include imaging the biological tissue at a depth that allows imaging of the dermo-epidermal junction (DEJ) of the biological tissue, e.g., a boundary between the superficial epidermis and the underlying deeper dermis of the biological tissue. RCM can enable noninvasive screening and diagnosis of cancers and/or burns while minimizing the need for biopsy.
RCM can produce grayscale en face images. Clinicians can find locating and delineating the DEJ based solely on RCM images to be challenging. Localization and delineation of the DEJ can be important in diagnosing skin and oral cancers. Melanomas and basal cell carcinomas can originate at the DEJ and can spread laterally from the DEJ in the epidermis and/or invade into the deeper dermis. The lateral spread and/or depth of invasion relative to the DEJ can be an important parameter for diagnosing the stage of cancer and/or determining whether to recommend a surgical or non-surgical treatment plan. RCM can have limited imaging depth. The limited imaging depth can be due to increasing aberrations and/or scattering at higher depths. Cancer and/or burn spreading depth can be difficult to assess using RCM alone.
Optical coherence tomography (OCT) is an imaging method that can provide cross-sectional images that show tissue morphology in depth and/or can be used to visualize the epidermal and dermal layers in human skin. Each layer can have different birefringence properties and appear differentiated in a polarization sensitive OCT (PS-OCT) image. OCT can allow visualization of tissue morphology in both the dermis and epidermis (e.g. to depths of about 1.5-2.0 mm). OCT can allow visualization of the DEJ. PS-OCT images can aid in evaluating collagen integrity in the dermis and tissue morphology. OCT images can aid in determining cancer depth spreading and/or burn injury depth. OCT typically does not provide adequate resolution to resolve sub-cellular details and diagnose early stage cancers.
Although other technologies for characterizing skin lesions, especially burns, have been previously tested (e.g. laser Doppler imaging, terahertz imaging, multispectral imaging, or even RCM and OCT independently), none of these technologies typically provides a substantially complete picture of tissue morphology and functionality. It is desirable for an imaging system to provide reliable and/or real-time data about tissue integrity. It is also desirable for an imaging system to provide viability status of biological tissue. It is also desirable for an imaging system to enable clinicians to efficiently and/or reliably assess epithelial lesions. It is also desirable for an imaging system to enable clinicians to efficiently and/or reliably monitor therapy outcomes.